"We are the only country in history that ever deliberately changed its ethnic makeup, and history has few examples of 'diversity' creating a stable society." - Richard Lamm, former governor of Colorado

Tuesday, June 26, 2007

Young African-American women and aggressive breast cancer

Lorie Williams thought for months that she might have a lump in her breast. But when the doctor said it was cancer, she was still stunned. After all, she was just 29 years old, no one in her family had ever had breast cancer, and she had never heard of anyone getting the disease so young.

"I was just numb," said Williams, who lives in Holly Springs, N.C. "I couldn't believe it was really happening. Then I just became hysterical."

Women such as Williams are the focus of an intense effort to solve one of the most pressing mysteries about breast cancer: Why are black women, who are less likely to get the disease than white women, more likely to get it when they are young -- and much more likely to die?

Now, researchers have uncovered a crucial clue: Black women, particularly young ones, get hit much more often by an aggressive form of breast cancer that is invulnerable to many of the latest treatments. The same deadly form of breast cancer turns out to be extremely common in parts of Africa where the slave trade was centered, indicating that genes play a role.

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Researchers using the latest molecular tools have discovered that breast cancer comes in at least five variations. One, called "triple-negative" because it lacks three key markers that distinguish tumors, grows quickly, recurs more often and kills more frequently. It is much harder to prevent and treat because it does not respond to the newest drugs.

A key insight came last year when a detailed genetic analysis of 496 breast tumors showed that a "basal-like" form of triple-negative cancer was startlingly more common among young black women, accounting for 39 percent of their cancers, compared with 16 percent of white women's.

"We found an important piece of the puzzle," said Lisa Carey of the University of North Carolina, who led the study. "This indicates that biology is important."

Other studies subsequently confirmed the findings, including one involving more than 50,000 California women published last month that found triple-negative tumors about twice as often among black women as among white women. It also found that triple-negative is also more frequent in Hispanics than in whites, though still less common than in blacks.

Some researchers, suspecting that the higher rate among African-Americans might stem from a genetic predisposition, have begun studying women in parts of Africa. They discovered that triple-negative is extremely common, accounting for some 70 percent of breast cancers in women tested in Nigeria and Senegal, for example.

"This suggests that there may be a genetic contribution," said Olufunmilayo Olopade of the University of Chicago, who is leading the research. "Is it because of genes common to African-Ancestry? Maybe there's a genetic contribution that we didn't appreciate."